Composition for hard facing



to protect them from abrasive wear.

Patented Sept. 23,1952

- OFFICE COMPOSITION FOR HARD FACING- Herbert J. Woock, Alhambra, Calif.

No Drawing.

12 Claims. 1

This invention relates to an improved hard facing composition by which a .hard metallic coating or facing can be applied to steel articles This application is a continuation-in-part of my copending application, Serial No. 643,761, filed January 26, 1946, now abandoned.

A primary object of the invention is to provide a hard facing composition that can be easily and quickly applied over the surface of a steel article tobe hard faced andwhich will enable the facing to be of the desired thickness or thinness at will. In many types of tools the article to be hard :faced is relatively thin and this is particularly true if the hard facingis to be applied adjacent a sharp or beveled edge. Heretofore, many-hard facings have been applied by welding onto the tool to be hard faced, a hard facing alloy. However, if the tool-is thin where the hardfacing is to be applied the welding procedure isapt to burn throughthe tool in effecting adequate penetration to secure the desired bond between the welded-on alloy and the metal of the tool. The improved composition enables a hard facing that is very thin to be applied under such circumstances without danger of burnin through the body of the tool. While the composition, is highly advantageous in applying thin layers or coatings of' hard facing material, it is not restricted thereto and enables a hard facing layer of any reasonable thickness to be applied when desired.

Another. object of the invention is to provide a hard facing composition which can be controlled and varied at will to produce a hard facinghaving the desired characteristics of hardness and abrasive resistance.

In its'simplified and preferred form the composition embodying the present invention consistsof a mixture of two preparedalloys and a flux. 1 first prepare one alloyfrom the following ingredients in approximatelythe following proportions by weight? Per cent These ingredients are mixed togethenmelted in a crucible, and poured into pigs, and the resulting alloy is then crushed and pulverized to particles of 60 mesh and smaller sizes.

I prepare a second alloy of the following in- Application December 17, 1949, Serial No. 133,670

gredients in approximately the following proportions by weight:

Per cent Nickel 8O Ferrosilicon (%-90% silicon) 20 Total These ingredients are also mixed together, melted in a crucible and poured into pigs, and crushed to approximately 60 mesh particles and finer sizes.

The final composition used consists of approximately 84% of the first alloy, above de scribed, 10% of the second alloy above described, and. 6% of a flux. Practically any'flux used in welding may be employed for this purpose which will perform the function of preventing oxidation of the molten metal and cause impurities to surface so that they may be removed on the completion of the hard facing as slag. The flux employed should also possess the property of acting as an adhesive for adhesively fastening the particles of the alloy to the base. steel that is to be hard surfaced. A preferred flux consists of the following:

. Per cent Diatomaceous earth 4 Borax 52 /2 Boric acid 26 Calcium chloride 16% The percentage of the flux is a percentage based on the weight of the entire metal and flux,that is, the 6% of flux employed constitutes six parts per cent by weight of the entire composition.

The mixture of the two alloys and the flux may be mixed in a dry state and may be kept in stock. At the time of use water is added to the mixture and it is violently agitated so as to hold as long as possible the metal alloy particles and the flux ingredients in suspension. The amount of water added is dependent to some extent upon the thickness of the hard facing that is to be applied. If the hard facing is to be very thin, considerable water is added so that the paste produced will be thin enough to spread readily over the surface to be hard faced. If a thicker hard facing is desired, less water is employed so that the paste will be somewhat thicker and can be applied as a thick coating. By maintainin the paste in a violently agitated condition up to the time that it is applied to the tool, a fairly even distribution of the particles of-the two alloys and the flux can be obtained. The tool that is thus coated is then dried or baked to remove all of the moisture. I prefer to :place the tool in an oven and dry it at a temperature of approximately 300 to 400 F. for a few minutes. When it is completely dried the flux acts somewhat as a mechanical adhesive attaching the particles of the alloys to the tool so that they will not be dislodged therefrom in the course of handling.

The applied coating of the paste which has been thus dried is then fused. This may be accomplished by playing on the coating the flame of an oxy-acetylene torch or the flame of an atomic hydrogen torch. In some situations a carbon arc may also be employed. If the tool is extremely thin or there are other considerations making it advantageous to do so, the tool may be placed in a furnace and heated until the applied coating fuses. When the paste fuses it will be found to be evenly distributed over the area to which it has been applied and on cooling it will produce a hard wear-resisting surface firmly attached to the base metal of the tool. If the base metalof the tool is thereafter to undergo heat treatment, this may be accomplished without disturbing or affecting the hard facing produced. I have found that other fiuxing ingredients may be used in lieu of calcium chloride; thus lithium chloride, magnesium chloride, and other metal chlorides that I have tried seem to perform; substantially the same function as calcium chloride. I have also employed in lieu of calcium chloride, potassium carbonate, sodium carbonate, and calcium carbonate, and while the resultsemploying the carbonates are not quite as goodfas when calcium chloride is used they are nevertheless satisfactory.

In some instances I find it advantageous to add to the flux an organic b-urnable adhesive such as for example gum arabic. Any other organic adhesive can be employed in lieu thereof which will serve to 'adhesively fasten the metal particles to the bas metal so that they will not become dislodged therefrom during handling after the baking operation. Such organic adhesive when employed merely burns out of the composition in the course of final fusing. The use of the organic adhesive, however, is not essential as in a large percentage of instances the drying of the fi'ux during the baking operation causes the flux to function as the adhesive in temporarily bonding the alloy particles to the base metal.

It will, of course, be appreciated that when the metal'ingredients and the flux are mixed with water the metallic ingredients tend to quickly settle unless violently agitated. It is possible to introduce into the composition along with the flux a suspending agent which will tend to keep the metallic particles in suspension. Kaolin (china clay) maybe used-for this purpose, and in the above described composition the diatomaceous earth functions in this manner to some extent. In the course of the final fusing these suspending agents, rise to the surface of the metal "while it is in a molten condition and enter or form the slag thereon which can be removed such as by a wire brush.

When it is desired to vary the hardness and some of the characteristics of the hard facing that is applied, a hard metal carbide can be added to the composition. Tungsten carbide, molybdenum carbide, and titanium carbide are all'suitable. These carbides, if employed, should be pulverized to 60 mesh and finer, and any proportion of metal carbide can be added from a trace up to 200% by weight of the composition;

The hardness of the composition resulting from the fusing varies to a large extent in direct proportion ,to the amount of the hard metal carbide that is added. Thus, if a substantial amount of hard metal carbide is added, the hardness and abrasive resistance of the hard facing is substantially greater than where only a trace of carbide is added.

Where a hard metal carbide is added it is usually desirable to increase the amount of flux to compensate therefor and to maintain th flux in the proportion of about 6% by weight of the entire metallic composition including the hard metal carbide. Also, when a hard metal carbide is added it is usually desirable to add mor of the second alloy which predominates in nickel. The hard metal carbide tends to raise the melting point of the composition but the addition of the nickel tends to compensate for this by lowering the melting point so that the melting point of the entire composition will remainapproximately the same.

In the composition of the two .metal alloys above described, th ferrosilicon ingredients is introduced primarily to render the resulting alloy brittle or friable so that it may be crushed or pulverized after having been poured into pigs. While the nickel ingredients in the second alloy could be added directly to the first alloy and alloyed therewith, I find that if this is done the alloy resulting from such a mixture of ingredients has a high melting point or fusing temperature. If the ingredients of the first alloy'as above given are melted, pigged, and pulverized separately, and the ingredients of the second alloy are separately melted, pigged, and pulverized, and'thereafter added, the paste produced, when subjected to fusing temperature has a lower melting point in that the nickel and ferrosilicon, being alloyed together, tend to melt ata lower temperature. The first described alloy seems to dissolve therein and afusing of the entire composition to take place at a lower temperature than would be the case if all ingredients were melted together in a single alloy, pigged, andv pulverized, .and used to form the paste. The use of. cobalt and boronin the first alloy above described may be regarded as optional but their presence is desirable.

By hard facing a steel tool by means of this.

composition'and in accordance with-the method described herein, a hard facing can be applied at a temperature below the melting. point of. the tool. The fusing temperature of the composition is at or below the sweating temperature ,of the average steel that is used for ordinary tools. Consequently, when the fusing is caused to take place ina furnace the body of the tool will not melt or burn through even though the tool may be extremely thin. The. thickness of the hard facing is controlled by controlling the thickness of the paste applied to the tool.

The ingredients that enter into the first alloy above described may bevaried inamount to a considerable extentiHI-hus; they may var-y through approximately the following ranges:

v 7 Percent Cobalt 0 to 20 Ferrochromium 1 32 to 52 Ferromanganese j 13 to 23 Boron -5. 0 to 20 Ferrosilicon v 5 to 15 Ferromolybdenum '6 to 15 In the second alloy the ferrosilicon,.content may bevaried from to and the nickel ingredient adjusted accordingly. The .composi: tion of the flux can be varied both as 13017116112: ture of the ingredient and its quantity greatly inasmuch as virtually any common flux used in welding can be employed and, reasonably satisfactory results secured. The relative proportions of the first alloy and the second prior to. the addition of hard metal carbide, if this is employed, can also be varied. Thus, the amount of the first alloy employed in the final composition may be raised or lowered above and below 84% as much as 10% either way at the expense of the second alloy and the flux. In a similar manner, the nickel-ferrosilicon. alloy mayconstitute more or less than 10% of thefinalcomposition. The percentages given, however, haveproven satisfactory and for these reasons these percentagesare set forth herein as indicative of the most satisfactory mannerin which the present composition may be compounded.

Various changes may be made in the details of the composition without departing from the spirit and scope of the invention as defined by the appended claims, wherein I claim:

1. A composition for producing a metallic hard facing comprising a mixture of two alloys and a flux of the type used in welding in the proportion of about 84% of the first alloy, 10% of the second alloy, and 6% of the flux, the first alloy resulting from the melting, pigging, and crushing of a mixture comprising about 10% cobalt, about 42% ferrochromium, about 18% ferromanganese, about 10% boron, about 10% ferrosilicon, and about 10% ferromolybdenum; the second alloy resulting from the melting, pigging, and crushing of about 80% nickel, and about 20% ferrosilicon.

2. A composition for producing a metallic hard facing comprising a mixture of two alloys and a fiux of the type used in welding in the proportion of about 84% of the first alloy, 10% of the second alloy, and 6% of the flux, the first alloy resulting from the melting, pigging, and crushing of a mixture comprising about 10% cobalt, about 42% ferrochromium, about 18% ferromanganese, about 10% boron, about 10% ferrosilicon, and about 10% ferromolybdenum; the second alloy resulting from the melting, pigging, and crushing of about 80% nickel, and about 20% ferrosilicon, and to which is added up to 200% by Weight of the foregoing composition of a hard metal carbide from the group consisting of tungsten carbide, molybdenum carbide and titanium carbide.

3. A composition for producing a metallic hard facing comprising a mixture of two alloys and a flux of the. type used in welding in the proportion of about 84% of the first alloy, 10% of the second alloy, and 6% of the flux, the first alloy resulting from the melting, pigging, and crushing of a mixture comprising about 10% cobalt, about 42% ferrochromium, about 18% ferromanganese, about 10% boron, about 10% ferrosilicon, and about 10% ferromolybdenum; the second alloy resulting from the melting, pigging, and crushing of about 80% nickel, and about 20% ferrosilicon, and a small amount of a heat destructible organic adhesive agent sufficient to cause the particles to adhere to the metal to be faced.

4. A composition for producing a metallic hard facing comprising a mixture of two alloys and a flux of the type used in welding in the proportion of about 84% of the first alloy, 10% of the second alloy, and 6% of the flux, the first alloy resulting from the melting, pigging,. and crushing of a mixture comprising about 10% cobalt, about 42% ferrochromium, about 18% ferromanganese, about 10% boron, about 10% ferrosilicon, and

about 10% ferrornolybdenum; the second alloy.

resulting from the melting, pigging, and crush.- ing of about nickel, and about 20% ferrosilicon, the flux including a small amount of an,

agent for assisting the maintaining of said alloys in suspension in water. i

5. A composition for producing ameta-llic hard facing comprising a mixture of two alloys and a flux of the type used in welding in the proportion of about 84% of the first alloy, 10% of the second alloy, and 6% of the flux, the first alloy resulting from the melting, pigging, and crushing of a mixture comprising about 10% cobalt,

about 142% ferrochromium, about 18%. ,ferro-H' manganese, about 10% boron, about l0%fer'rosilicon, and about 10% 'ferromolybdenum; the second alloy resulting from the melting, pigging, and crushing of about 80% nickel, and about 20% .ferrosilicon, and to which is added a small amount of clay for assisting in maintaining said alloys in suspension in water.

6. A composition for producing a metallic hard facing comprising a mixture of two alloys and a flux in the proportion of about 84% of the first alloy, 10% of the second alloy, and approximately 6% of the fiux, the first alloy resulting from the melting, pigging, and crushing of ferrochromium 32 to 52%, ferromanganese 13 to 23%, ferrosilicon 5 to 15%, and ferromolybdenum 6 to 15%, the second alloy resulting from the melting, pigging, and crushing of about 80% nickel and 20% ferrosilicon.

'7. A composition for producing a metallic hard facing comprising a mixture of two alloys and a flux in the proportion of about 84% of the first alloy, 10% of the second alloy, and approximately 6% of the flux, the first alloy resulting from the melting, pigging, and crushing of ferrochromium 32 to 52%, ferromanganese 13 to 23%, ferrosilicon 5 to 15%, and ferromolybdenum 6 to 15%, the second alloy resulting from the melting, pigging, and crushing of about 80% nickel and 20% ferrosilicon, the above ingredients being crushed to 60 mesh and finer.

8. A composition for producing a metallic hard facing comprising a mixture of two alloys and a flux of the type used in welding in the proportion of about 84% of the first alloy, 10% of the second alloy, and 6% of the flux, the first alloy resulting from the melting, pigging, and crushing of a mixture comprising about 10% cobalt, about 42 ferrochromium, about 18% ferromanganese, about 10% boron, about 10% ferrosilicon, and about 10% ferromolybdenum; the second alloy resulting from the melting, pigging, and crushing of about 80% nickel, and about 20% ferro silicon, the above ingredients being crushed to 60 mesh and finer.

9. A composition for producing a metallic hard facing comprising a mixture of two alloys, a flux, and additional hard metal carbides in the proportion of from a trace to 60% of hard metal carbides, 10% of an alloy resulting from the fusion of 80% nickel and 20% ferrosilicon, 6% of the flux and the remainder of the composition composed of an alloy resulting from the fusion of about 10% cobalt, 42% ferrochromium, 18% ferromanganese, 10% boron, 10% ferrosilicon, and 10% ferromolybclenum, all in a finely powdered,

7 crushed? ond'ition capable 01 passing through a,- 60'mesh screen. t I

composition for producing 91 metallic hardafaeing comprising a; mixture of two alldys, ani addition of a hard m'et'al carbide and a) flux in thes'pr'opdrtions of from a;v traceto 66% hard 80% nickel: and about 20 fgrrosilicon; atll crushed: to fineness of. at least 60 meshscreen sizetand mixed in powdered formr 131.. A vi compositio'n for producing a; metallic" hartt facing. comprising a mixture of tiwb-alldys ande a fiux of that type used in weldingmetal in the:prnporti'onof frm 74%- to 94% of the firstalloy: and from 6% to 26% of the second alloy andmemainder' the. flux, the first alloy resulting from the me1t'ing;(pi'ggi'ng. and crushing of a mixture comprising about 10% cobalt, about 42% frrbchromium; about 18% ferromang'anese; about 10% boron; about." 10% fe'rrosi'l-i'cim, 'aim'l smut 10 ferromolybdenum, fihes'cond' alloy resulting fifOm the: melting, pigging and c'rushifig of about 80% nrcketand about 20% feHOs'iH- 0011 we above ingredients being: crushed 1:0"60 mesh and finer;

12 A composition for producing a metallic hard' facing: comprising a; mixture of two alloys a; flux? o fth'e typaused' in welding an' additional hard metal carbides in the proportions of f rom a tra1ceto"60 dfi hard: metal carbides, 6% of flux; and the" remainder comprising two alloys ot1'rom 7'4*% to" 94% of the first alloy and from 6%: to: 26% of' the second alIoy; the first alloy resultingkfrom the melting;piggingand crushmg of ferrochrdmium 32' to 52%,f rromaingdng'ei6 1-3 to 23 f erx 'osil-icon 5 to ferromo1ybdenuhi 6 to 15%;.and' the second aHo'y resulting from the melting} pigging and crushingof afiout' 80% nicker sJI Id ferrosi'lico'fi, the abb've i'ngredients being crushedtofiwmes'h"and flner; I

' HERBERT J WOOCK.

Nbxreferences cited. 

1. A COMPOSITION FOR PRODUCING A METALLIC HARD FACING COMPRISING A MIXTURE OF TWO ALLOYS AND A FLUX OF THE TYPE USED IN WELDING IN THE PROPORTION OF ABOUT 84% OF THE FIRST ALLOY, 10% OF THE SECOND ALLOY, AND 6, OF THE FLUX, THE FIRST ALLOY RESULTING FROM THE MELTING, PIGGING, AND CRUSHING OF A MIXTURE COMPRISING ABOUT 10% COBALT, ABOUT 42% FERROCHROMIUM, ABOUT 18% FERROMANGANESE, ABOUT 10* BORON, ABOUT 10% FERROSILICON, AND ABOUT 10% FERROMOLYBDENUM; THE SECOND ALLOY RESULTING FROM THE MELTING, PIGGING, AND CRUSHING OF ABOUT 80% NICKEL, AND ABOUT 20% FERROSILICON. 